Fermentation medium and oxygen transfer conditions that maximize the xylose conversion to ethanol by Pichia stipitis

The xylose conversion to ethanol by Pichia stipitis was studied. In a first step, the necessity of supplementing the fermentation medium with urea, MgSO4 × 7H2O, and/or yeast extract was evaluated through a 23 full factorial design. The simultaneous addition of these three nutritional sources to the fermentation medium, in concentrations of 2.3, 1.0, and 3.0 g/l, respectively, showed to be important to improve the ethanol production in detriment of the substrate conversion to cell. In a second stage, fermentation assays performed in a bioreactor under different KLa (volumetric oxygen transfer coefficient) conditions made possible understanding the influence of the oxygen transfer on yeast performance, as well as to define the most suitable range of values for an efficient ethanol production. The most promising region to perform this bioconversion process was found to be between 2.3 and 4.9 h−1, since it promoted the highest ethanol production results with practically exhaustion of the xylose from the medium. These findings contribute for the development of an economical and efficient technology for large scale production of second generation ethanol

Avaliação do processo de bioprodução de etanol a partir de xilose pela levedura Pichia Stipitis NRRL Y-7124 em reator de bancada

A produção de etanol pela levedura Pichia stipitis foi avaliada em reator de bancada sob diferentes condições de aeração e agitação em meio semi-sintético contendo xilose (90,0 g/L) como principal fonte de carbono. Os ensaios foram realizados segundo um planejamento fatorial 2² variando-se a aeração (0,25 a 0,75 vvm) e a agitação (150 a 250 rpm). Dentro da região de transferência de oxigênio estudada, o fator de conversão de substrato em produto (Y P/S) e a produtividade volumétrica em etanol (QP) sofreram pouca influencia das variáveis avaliadas. Diante disto, a máxima concentração de etanol acumulada foi o parâmetro adotado como principal critério de seleção das condições de processo. A máxima concentração de etanol, cerca de 27 g/L, foi obtida a 250 rpm de agitação e aeração de 0,25 vvm (kLa = 4,9 h-1). Nestas condições, a conversão de substrato em produto (Y P/S), eficiência (η) e produtividade em etanol (QP) foram de 0,32 g/g, 63 % e 0,32 g/L.h, respectivamente.SANTANDERFAPESPCAPESCNP

Paraneoplastic sclerodermiform syndrome--case report.

Occasionally, auto-immune diseases may emerge as paraneoplastic syndromes. This is especially recognized in the case of polymyositis/dermatomyostis, but it is an extremely rare event in systemic sclerosis (SSc). The authors report the case of a sixty-year-old woman who presented with Raynaud's phenomenon and rapidly progressing skin thickness of the forearms, hands and lower limbs. Patient evaluation revealed a colorectal carcinoma. The patient was referred to the oncology department. This concomitance of cancer and SSc with rapid progression of the latter, suggests that the scleroderma might have a paraneoplastic origin. Such an hypothesis deserves consideration in every case as early diagnosis may be decisive to control the progression of either disease

Bio-detoxification of mycotoxins by lactic acid bacteria from different food matrices

Lactic acid bacteria (LAB) play a key role in the biopreservation of a wide range of fermented food products, such as yogurt, cheese, fermented milks, meat, fish, vegetables (sauerkraut, olives and pickles), certain beer brands, wines and silage, allowing their safe consumption, which gave to these bacteria a GRAS (Generally Recognised as Safe) status. Besides that, the use of LAB in food and feed is a promising strategy to reduce the exposure to dietary mycotoxins, improving their shelf life and reducing health risks, given the unique mycotoxin decontaminating characteristic of some LAB. Mycotoxins present carcinogenic, mutagenic, teratogenic, neurotoxic and immunosuppressive effects over animals and Humans, being the most important ochratoxin A (OTA), aflatoxins (AFB1), trichothecenes, zearalenone (ZEA), fumonisin (FUM) and patulin. In a previous work of our group it was observed OTA biodegradation by some strains of Pediococcus parvulus isolated from Douro wines. So, the aim of this study was to enlarge the screening of the biodetoxification over more mycotoxins besides OTA, including AFB1, and ZEA. This ability was checked in a collection of LAB isolated from vegetable (wine, olives, fruits and silage) and animal (milk and dairy products, sausages) sources. All LAB strains were characterized phenotypically (Gram, catalase) and genotypically. Molecular characterisation of all LAB strains was performed using genomic fingerprinting by MSP- PCR with (GTG)5 and csM13 primers. The identification of the isolates was confirmed by 16S rDNA sequencing. To study the ability of LAB strains to degrade OTA, AFB1 and ZEA, a MRS broth medium was supplemented with 2.0 g/mL of each mycotoxin. For each strain, 2 mL of MRS supplemented with the mycotoxins was inoculated in triplicate with 109 CFU/mL. The culture media and bacterial cells were extracted by the addition of an equal volume of acetonitrile/methanol/acetic acid (78:20:2 v/v/v) to the culture tubes. A 2 mL sample was then collected and filtered into a clean 2 mL vial using PP filters with 0.45 m pores. The samples were preserved at 4 °C until HPLC analysis. Among LAB tested, 10 strains isolated from milk were able to eliminate AFB1, belonging to Lactobacillus casei (7), Lb. paracasei (1), Lb. plantarum (1) and 1 to Leuconostoc mesenteroides. Two strains of Enterococcus faecium and one of Ec. faecalis from sausage eliminated ZEA. Concerning to strains of vegetal origin, one Lb. plantarum isolated from elderberry fruit, one Lb. buchnerii and one Lb. parafarraginis both isolated from silage eliminated ZEA. Other 2 strains of Lb. plantarum from silage were able to degrade both ZEA and OTA, and 1 Lb. buchnerii showed activity over AFB1. These enzymatic activities were also verified genotypically through specific gene PCR and posteriorly confirmed by sequencing analysis. In conclusion, due the ability of some strains of LAB isolated from different sources to eliminate OTA, AFB1 and ZEA one can recognize their potential biotechnological application to reduce the health hazards associated with these mycotoxins. They may be suitable as silage inoculants or as feed additives or even in food industry.Acknowledgements This work was funded by FEDER funds through the COMPETE and by national funds through FCT, Ref. FCOMP-01-0124-FEDER-028029 and PTDC/AGR-T EC/3900/2012, respectively. Luís Abrunhosa received support through grant Incentivo/EQB/LA0023/2014 from ON.2 O Novo Nort

Epigenetic modulators as therapeutic targets in prostate cancer

Prostate cancer is one of the most common non-cutaneous malignancies among men worldwide. Epigenetic aberrations, including changes in DNA methylation patterns and/or histone modifications, are key drivers of prostate carcinogenesis. These epigenetic defects might be due to deregulated function and/or expression of the epigenetic machinery, affecting the expression of several important genes. Remarkably, epigenetic modifications are reversible and numerous compounds that target the epigenetic enzymes and regulatory proteins were reported to be effective in cancer growth control. In fact, some of these drugs are already being tested in clinical trials. This review discusses the most important epigenetic alterations in prostate cancer, highlighting the role of epigenetic modulating compounds in pre-clinical and clinical trials as potential therapeutic agents for prostate cancer management

Multitask ATPases (NBDs) of bacterial ABC importers type I and their interspecies exchangeability

We would like to thank Herminia de Lencastre (ITQB-AX NOVA), Adriano Henriques (ITQB-AX NOVA) and PaulaTamagnini (i3S) for the gift of chromosomal DNA, Paulo Tavares (I2BC-CNRS) and Adriano Henriques for the gift of flagellin and anti-sigmaA antibodies, respectively, and Diogo Pereira for carrying out some growth kinetic assays. This work was supported by the FundacAo para a Ciencia e a Tecnologia [Grant Numbers PTDC/BIA-MIC/30696/2017 to ISN and UID/Multi/04378/2019 to Unidade de Ciencias Biomoleculares Aplicadas UCIBIO; and fellowship PD/BD/105737/2014 to F.L.].ATP-binding cassette (ABC) type I importers are widespread in bacteria and play a crucial role in its survival and pathogenesis. They share the same modular architecture comprising two intracellular nucleotide-binding domains (NBDs), two transmembrane domains (TMDs) and a substrate-binding protein. The NBDs bind and hydrolyze ATP, thereby generating conformational changes that are coupled to the TMDs and lead to substrate translocation. A group of multitask NBDs that are able to serve as the cellular motor for multiple sugar importers was recently discovered. To understand why some ABC importers share energy-coupling components, we used the MsmX ATPase from Bacillus subtilis as a model for biological and structural studies. Here we report the first examples of functional hybrid interspecies ABC type I importers in which the NBDs could be exchanged. Furthermore, the first crystal structure of an assigned multitask NBD provides a framework to understand the molecular basis of the broader specificity of interaction with the TMDs.publishersversionpublishe

The prognostic value of worsening renal function and its timing

Copyright © 2023 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.INTRODUCTION: Acute decompensated heart failure (ADHF) admissions are frequently complicated by different patterns of serum creatinine (SCr) elevation. We aimed to assess the prognostic impact of worsening renal function (WRF) based on the timing of its occurrence. METHODS: This was a retrospective cohort of patients admitted for ADHF. Standard WRF was defined as an increase in SCr of ≥0.3 mg/dl during hospitalization. WRF timing was classified as early (within 48 hours of admission) or late (>48 hours). Acute kidney injury (AKI) at admission was defined as a rise in SCr of ≥0.3 mg/dl from outpatient baseline measurement to first measurement at admission. The primary endpoint was a composite of all-cause mortality or hospitalization for cardiovascular events at one-year follow-up. RESULTS: Overall, 249 patients were included (mean age 77±11 years, 62% with preserved left ventricular ejection fraction). Early WRF occurred in 49 patients (19.7%) and was associated with a higher risk of the primary outcome (HR 2.49; 95% CI 1.66-3.73), whereas late WRF was not (p=0.411). After stratification for the presence of early WRF and/or AKI at admission, only patients with early WRF but no AKI at admission and patients with both AKI at admission and early WRF showed a higher risk of the primary outcome after multivariate Cox regression. CONCLUSION: Early WRF was associated with a higher risk of the primary outcome. The timing of WRF seems to be an important factor to take into account when considering the prognostic impact of creatinine variations during hospitalization for ADHF.proofepub_ahead_of_prin

Characterization of wine fermentations using fiber optic-mediated UV-VIS-SWNIR spectroscopy

Spectroscopy is widely used in biological sciences, being applied to liquids, pastes, powders, films, fibers, gases and surfaces. It makes possible to characterize proteins, peptides, lipids, membranes and carbohydrates in pharmaceuticals, foods, plants or animal tissues. It can also provide detailed information about the structure and mechanism of action of molecules. UV-VIS-SWNIR spectroscopy has not been used for fermentations characterization. This is possibly attributed to the fact that UV-VIS spectroscopy records transmissions between electron energy levels from molecular orbitals, which do not have a direct relationship with the presence/concentration of compounds, instead of vibrational or structural oscillation of molecular groups as in the infrared region, where such relationship is more straightforward. UV-VIS-SWNIR spectroscopy registers many features such as fluorescence and vibrational resonances due to energy decay of exited electrons, which may provide highly accurate fingerprinting of metabolites and metabolic state of the fermentation, provided that an adequate data treatment and interpretation system is available. In this work we explore the use of fiber optics UV-VIS-SWNIR spectroscopy to characterize wine fermentations of a Saccharomyces cerevisiae collection. This collection comprises 114 strains (among which almost 40 are sequenced strains), between industrial strains used for winemaking, brewing, bakery, distillery (sake, cachaça) and ethanol production, natural isolates obtained in winemaking environments, and also strains from particular environments (e.g. pathogenic strains, isolates from insects, fruits and oak exudates). Individual fermentations were carried out in 100 mL wine (cv. Loureiro) must for each of the 114 strains, and the growth rate, CO2 release and glucose concentration were followed throughout fermentation. When glucose concentration was below 5 g/L, cells were collected and immediately frozen and stored for fiber optics spectroscopy analysis. Transmittance fiber optics UV-VIS-SWNIR spectroscopy was used to record the spectra between 200 and 1200 nm, using a highly sensitive scientific-grade spectrometer (Ocean Optics, QE65000) for maximum resolution. The procedure was performed in a special probe container designed to isolate the environmental light and maintain the probe horizontally, to prevent the deposition of debris in the mirrored surface. The following experimental procedure was performed: spectra were obtained at room temperature at previously stabilized (20 min) light sources; dark spectra were recorded and measurements were taken with linear and electric dark correction. Light spectra were statistically monitored, assessing the reproducibility of the light source by regular light measurements. Twenty spectra replicates were recorded for each fermentation. Results show that after appropriate preprocessing and signal classification, fiber optics UV-VIS-SWNIR spectroscopy is a robust technique for characterize different wine fermentations, being able to characterize and differentiate the fermentation of different strains of S. cerevisiae based on their origins, by each spectroscopic fingerprinting. This technique associated with other physico-chemical information can benefit the creation of an information system capable of providing extremely detailed information about physical processes and molecular biology that will aid both scientists and engineers to study and develop new biotechnological products.Fundação para a Ciência e a Tecnologia (FCT